Method of treating metal parts to prevent solder adhering thereto.



L. W. DOWNES. METHOD OF TREATING METAL PARTS TO PREVENT SOLDER ADHERING THERETO.

APPLICATION FILED JULY 10,1917. 1,254,663. Patented Jan. 29, 1918 W AW 1? y x v iiurrnn STATES PATENT OFFIE.

LOUES N. DOVNES, OF PROVIDENCE,

P-INY, OF PROVIDENCE. RHODE ISLAND, A CORPORATION' F RHODE ISLAND.

'METHQB F TREATING: METAL PARTS TO PREVENT SOLIDER ADHERING THEBETO.

which the following is a specification.

The object of this invention is to providev a methcd of preventing the soldering to-' gether of the parts of an electric fuse when ihev link therein is blown, by treating the surfaces of the metal parts previous to positioning them in the casing so as to prevent the adhering. of molten metal thereto.

It is found inpractice that when a reloadable fuse of this character is constructed without a filling of granular material and that when a fusible element blows in it, the molten metal or metallic vapor in its effort to escape is forced into the joints at the ends, producing the effectof soldering the whole together, often times so rigidly that the fuse is destroyed in trying to get it apart.

The figure in the drawin illustrates one form of reloadable fuse designedto be'constrncted and operated without a filling of granular material, which isgzdapted to be treated by my new non-solderin method.

Reloadablefuses of the cartridge type are usually constructed with a tubular casing 10 of fiber or other suitable insulating material, the ends of which are made up of a plurality of metal parts connected thereto, which parts m'ay be constructed in any suitable or convenient way, one form of which is herein shown in the drawing.

In fuses of this character ends 11 of the fusible link 12 are connected to these metal parts, the link itself being formed of a thin body of metal capable of fusing at a comparatively low temperature and when melted the molten metal is blown with such violence against the metal parts of the casing ends that it finds its way into the joints which are thereby effectually soldered together, for instance in a fuse of the structure herein illustrated the molten metal will Specification of Letters Patent.

claims.

the opposite Patented Jan; an, aura.

Application filed July 10, 1917. Serial No. 179,668.

find its way through theopening 13 in the washer 14 and into the -threads 15 thereby soldering this washer rigidly to its sleeve 1?) and the two threaded members lei/and 1'2 firmly together, rendering it practically impossible to get the fuse apart without breaking some portion thereof.

To obviate this serious ditiiculty I have provided a simple, practical and very efi'ective method of treating these parts before they-are positioned in the casing, so as to effectually prevent the adhering of the molten metal thereto. When so treated, no

will .not be soldered together.

One simple method is to subject the parts to heat in an oxidizing. medium before posi tioning them" in the casing, but any suitable. method of treating this metal to prevent the adhering of the solder thereto will fall with- RHODE ISLAND, ASSIGNOR TO D & W FUSE CQM- matter how violent the rupture, the parts be treated. with my improved method, but

the parts of fuses of any construction may be so treated to effect this result.

The scope of this invention limited only by the terms of is defined and the appended 1. A method of preventing the soldering together of the metalparts of an electric fuse by the blowing of the inclosed fuse link consisting of treating the metal surfaces to prevent adhering of the molten metal thereto.-

2. A method of preventing the soldering together of the metal parts of an electric fuse-by the melting of the link therein, consisting of coating the exposed surface of the metal parts with a non-solder-adhering material.

3. A method of preventing soldering together of the by the melting of the link therein consisting in oxidizing't e surfaces of the metal parts.

{1. A method of preventing soldering together of thp metal parts of an electric fuse y the melting of the link therein consisting in the application of chemicals to the sur- In testimony whereof I affix my signature faces of the metal parts to oxidize the same. in presence of two Witnesses. 5. A method of preventing the soldering together of the metal parts of an electric LOUIS W. DOWNES. 5 fuse When the link therein is blown consist- Witnesses:

ing in subjecting the parts to an oxidizing P. 0. BAKER,

heat before being positioned in the fuse. (meme W. STEERE. 

